A two-factor correlation for predicting friction factor in dispersed oil-water flow with drag-reducing polymers

Abstract

It is common knowledge that the most important parameter in the design and operation of pipeline transportation is the pressure drop. So far, little attention has been devoted to the development of predictive models for the pressure drop of the oil-water flow with DRP and the few reported studies considered Reynolds number as the only factor resulting to poor prediction. Therefore, this study was focused on developing an empirical correlation for adequately predicting the friction factor of a polymer-containing dispersed oil-water flow using mixture Reynolds number of the flow and molecular weights of the polymers as input factors. The oil-water flow was carried out in a 24-m-long, 30.6-mm-ID horizontal acrylic pipe using twelve acrylamide-based drag-reducing polymers of different molecular weights. The mixture velocities considered were 0.8, 1.0, 1.2, and 1.5 m/s with input oil volume fractions of 0.1, 0.3, and 0.5. The results reveal that the friction factor of the oil-water flow with DRPs was adequately fitted with combined mixture Reynolds number and polymer molecular weight using a power law (R2 = 0.95 and standard deviation, PSD = 13.18%). Overall, the developed correlation also showed good performance when used to predict friction factors of similar published dispersed oil-water flows.